A typical communication system, such as a trunked or conventional communication system, comprises a communication resource allocator, a plurality of communication resources, a plurality of consoles, and a plurality of communication units or subscriber units. Generally, the plurality of communication units, which may be mobile vehicle units or portable personal units, are arranged into related communication groups. For example, communication units operated by a city's police force may form one communication group, while communication units operated by the city's fire department, dog catcher units, highway crews, and civil engineers may form other communication groups. The communication groups may be further divided into sub-groups; for example, the police communication group may be divided by districts such as police 1, police 2, etc.
Typically, communication units in a trunked communication system are arranged into talk groups, where the talk groups share the plurality of communication resources on an "as requested basis". For a communication unit to access a communication resource, it transmits an inbound signalling word (ISW) to the communication resource allocator via a control communication resource. If a communication resource is available, the communication resource allocator transmits an outbound signaling word (OSW) indicating which communication resource is assigned to the requesting communication unit. (The OSW is also received by all communication units, however, only the communication units in the same talk group as the requesting communication unit will affiliate themselves with the assigned communication resource such that they may communicate to each other via the assigned communication resource.) In contrast, communication units in a conventional communication system access a permanently assigned communication resource by activating a push-to-talk (PTT) button, or similar accessing process, to notify the communication resource allocator that the communication unit is accessing the communication resource. (There are other differences between trunked and conventional systems but they are not relevant to this invention.)
The plurality of consoles, which may be devices as defined in Motorola Inc. publication No. R4-2-37C, Mar. 1988, entitled System Planner, typically comprise a plurality of channel control modules (CCMs), where each CCM is assigned a communication group and/or subgroup. The assigned communication groups and/or subgroups are presented to an operator of the console such that the operator may monitor and perform supervisory functions for each of the presented communication groups and/or subgroups. The supervisory functions a console may perform comprise resetting emergency conditions, manually reconfiguring the system, and transmitting at a priority level. Resetting emergency conditions consists of answering an emergency call, resetting audio and/or visual emergency call indicators and deactivating the manual system reconfiguration. However, these supervisory functions can only be manually performed for presented communication groups and/or subgroups.
By limiting a console to monitoring and manually performing supervisory functions for presented communication groups only, communication system efficiency may not be optimal. Furthermore, such communication systems may require additional consoles and operators to supervise additional communication groups, thereby increasing the space requirements and cost of these systems. Therefore, a need exists for a communication system that allows consoles to monitor unpresented communication groups as well as presented communication groups and to automatically perform at least some supervisory, or communication, functions for unpresented communication groups as well as presented communication groups.